Steam traps



July 3, 1962 D. B. DEEKS 3,042,363

STEAM TRAPS Filed June 2, 1960 2 Sheets-Sheet 1 INVENTO/P DOUGLAS 8.DEEKS ATTORNEYS United States Patent 3,042,363 STEAM TRAPS Douglas B.Decks, 197 Forest Hill Road, Toronto, Ontario, Canada Filed June 2,1960, Ser. No. 33,588 7 Claims. (Cl. 251-362) This invention relates tosteam traps, and more particularly to means of retaining the valve seattherein as to make it easily removable when required.

At the present time, three general methods are employed for retainingthe valve seat in steam traps: (a) screw threading the seat into thehousing or securing by a pressed fit; (b) connecting the seat within thehousing by screws; and (c) employing a coil spring on the valve assemblyto apply pressure thereto when the cap of the trap is secured in place.

The first method presents some difiiculty as special tools are usuallyrequired to enter the trap and accomplish the removal of the seatwhereas following a period of use under heat conditions, the screwthreaded union or pressed fit may seize so that it may be necessary toremove the trap from the line in order to remove the seat. In the secondinstance, it is necessary to remove the seat by means of a screw driver,socket wrench or other special tool and one may run the risk ofstripping the threads whereas under heat conditions, the screws may alsoseize so that this form of construction has equal disadvantages with thefirst.

The third method has practical advantages over the first two by reasonof the ease of removal of the seat when desired. However, due to extremeheat conditions, the force of the spring will be weakened which may tendto permit the seat to give. Of course, the higher the pressure thehigher the temperature and consequently under higher pressures, it wouldtend to seat less firmly and could leak. Thus, whereas the third typehas advantages over the first two, it has a disadvantage not apparent inthe others but in any case, all have the disadvantages outlined.

The present invention seeks completely to overcome the disadvantages ofall these types of steam traps by providing a means of securing thevalve seat in a simple manner much that it will be tight at all times inoperation and will tend to seat even more firmly under higher pressureand heat conditions and which has the particular advantage that it isvery readily removed when necessary.

The invention generally comprises a free seating valve seat combinedwith bimetallic means 50 applied as to exert firm seating pressure undernon-operating conditions and which seating pressure increasesproportionately under operating conditions with increased steam pressureand heat.

The invention will be clearly understood by reference to the followingdetailed specification taken in conjunction with the accompanyingdrawings.

In the drawings:

FIGURE 1 is a longitudinal section taken through one form of bimetalsteam trap illustrating one manner in which the bimetal retainingelement may be applied to the freely fitted seat.

FIGURE 2 is an exploded perspective of the foraminous cylinder andbimetallic disc cooperating therewith as incorporated in FIGURE 1.

FIGURES 3, 4 and 5 are fragmentary sections through part of a steam trapof the type shown in FIGURE 1 illustrating alternative means of causingpressure engagement between the bimetal element and the seat.

FIGURE 6 is a bottom plan view of a form of bimetallic elementarrangement which may be employed as in FIGURE 5.

3,l]i42,363 Patented July 3, 1962 FIGURE 7 is a fragmentary view of asteam trap structure showing a further alternative means of causing thebimetallic element to engage the seat under pressure; and

FIGURE 8 is a further fragmentary section of a trap showing anotheralternative manner of mounting the bimetallic element in pressureengagement With the seat.

Referring to the drawings and to FIGURES l and 2 in the first instance,A indicates a steam trap as a whole having a body cavity 10 normallyclosed by the cap B and which includes a valve seat C. The body cavityis in communication with the steam passages 11 and 12, communicationbetween the two being controlled by means of the valve D operated in theusual manner by means of multiple disc bimetallic unit E as to cause thevalve to seat under predetermined conditions of steam pressure.

According to the present invention, the valve seat C is freely fitted inthe opening 13 between the steam passage 11 and the body cavity 10 as tobe readily removable when this may be necessary. The valve seat C, ofcourse, is seated either in conjunction with or without a. gasket 14,according to the construction that may be employed, and to hold the seatfirmly in position I employ bimetallic element 15, extendingtransversely of the longitudinal axis of the valve seat and shown hereas a composite disc which is engaged by the foraminous cylinder 16, inturn engaged by the cap B of the body cavity so that the bimetallicelement is placed under tension and in turn engages the seat underpressure to retain it firmly in position under non-operating conditionsof the valve. Consequently, under operating conditions when hotcondensate or heat from steam pressure enters the body cavity thebimetallic element is caused to engage the seat with proportionatelyincreasing pressure having regard to the fact that the bimetalliccombination is such as to bias the bimetallic element under heatconditions and cause it to apply proportionately increasing forceagainst the seat. The higher the steam pressure the more firmly the seatwill be held in position, as steam temperature always rises with steampressure. Saturated steam only adds to the efi'ectiveness of the device.

It is obvious from a consideration of this structure that it may bedismantled for inspection purposes or the like with great case since itis only necessary to remove the cap B closing the body cavity 15 and thecylinder is readily removed whereas the complete working unit embodyingthe valve and valve seat is freely withdrawable without necessity oftools of any kind. It is, of course, apparent that the bimetallicelement 15 though shown as a disc, may readily take the form of a bar ora plurality of bars as may be deemed expedient.

In the form of construction illustrated in FIGURE 3, it will be notedthat the bimetallic element 15a is engaged with the valve seat C underpressure by means of lugs 17 projecting from the body wall into the bodycavity. In the case of FIGURE 4, the valve seat is engaged by a plate orbar 18 which in turn is engaged or may have secured thereto thebimetallic elements 19 disposed in the direction of the longitudinalaxis of the valve seat and which extend through the opening of the bodycavity to be engaged by the cap B when mounted as to cause such elementsto exert a physical pressure force on the plate 18. These elements arelikewise biased as to increase the pressure force of the plate 18 on thevalve seat proportionately to heat increase by steam pressure or hotcondensate.

In the case of FIGURE 5, the bimetallic element 20 which may be in the-form of a bar, a disc or a plurality of angularly disposed bars such asshown in FIGURE 6 is engaged with the valve seat C under pressure bymeans of rods or bolts 21 which may be carried by or engaged by the capB so as to exert a pressure on element 20 when the cap is placed inposition, thus in a .3 similar manner to retain the valve seat firmly inposition under nonoperating conditions. The element 20 is, of course,biased in a similar manner as described to increase pressure engagementwith the seat under conditions of heat.

In the case of FIGURE 7 an alternative to the construction of FIG. 3 isshown for applying pressure to the bimetallic element. Instead ofemploying the lugs 17, as in FIG. 3, the cap F of the valve body isscrew threadedly engaged as at 22 with the body and is formed with aninwardly projecting shoulder 23 such that it will engage the bimetallicelement 24 and achieve a similar condition for operating purposes, asdescribed in FIG. 3.

Referring to FIGURE 8 wherein a different type of trap body isillustrated, the bimetallic element 25 is engaged under pressure withthe valve seat C by anchoring one end in a suitably provided recess inthe body wall and anchoring the other end in a suitably formed recess inthe cap B as to achieve a condition of pressure engagement between thebimetallic element and the freely mounted seat and which obviously willoperate in a similar manner to the other general examples as to increasepressure on the seat proportionately with increase of heat conditions.

In essence, the examples above given will clearly indicate that thebasic principle of the invention is the exertion of an increasingpressure on the valve seat by a bi metallic element suitably anchored toachieve a seat holding pressure under non-operating conditions and toprovide for increased pressure between the element and seat underoperating conditions of increasing heat and/ or increasing steampressure. It should be understood, of course, that the illustrationsgiven above are by way of general example and that the principle canalso be applied equally to other types of bimetal steam, traps, bucketsteam traps, fiow steam traps and thermostatic bellows or diaphragmsteam traps. It will also be equally obvious, in relation to theirvarious types, that by reason of this extremely simple constructionemploying a freely mounted valve seat, dismantling to any extentnecessary is accomplished in an extremely simple operation upon removalof the body cap and without the necessity of special tools. Obviouslyalso it eliminates difficulties arising from seizure of the valve seatwhich may occur in known types of traps wherein the seats are not freebut specially fastened in position.

What I claim as my invention is:

1. In a steam trap, a valve seat freely fitted therein,

means for retaining said seat firmly in one immovable set positioncomprising bimetallic means engageable with said seat, and meansco-operating with said bimetallic means to engage it with said seatunder pressure during non-operating conditions of said trap, saidbimetallic means being biased to increase its pressure on said seatunder operating conditions of heat caused by steam pressure or hotcondensate, and retain said seat immovable in said set position undersaid latter conditions.

2. A device as claimed in claim 1 in which the bimetallic means isdisposed transversely to the longitudinal axis of the valve seat.

3. A device as claimed in claim 1 in which the bimetallic means isdisposed substantially in the direction of the longitudinal axis of thevalve seat.

4. A device as claimed in claim 1 in which the cooperating pressureapplying means is initiated through a closure member for the trap whensaid closure member is secured in position.

5. A device as claimed in claim 1 in which the bimetallic element is inthe form of a transverse element intersecting the longitudinal axis ofthe valve seat, and said co-operating means comprises means extendingbetween a closure member for said trap and said bimetallic means toapply pressure on said element when said closure is secured in position.

6. A device as claimed in claim 5 in which said element is a disc andsaid co-operating means is an orificed cylinder.

7. A steam trap including a steam passage line comprising a body havinga cavity therein having openings communicating with said steam line, avalve seat freely disposed fitted in one of said openings, and pressuremeans for maintaining said seat in immovable position therein duringnon-operating conditions of said trap, said pressure means including atleast one bimetallic element, biased to increase the pressure force ofsaid pressure means on said seat under operating conditions of heatcaused by steam pressure or hot condensate, as to ensure saidimmovability of said seat under operating conditions.

References Cited in the file of this patent UNITED STATES PATENTS2,495,226 Crago Jan. 24, 1950

